1. Field of the Invention
The present invention relates to an exposure apparatus, a substrate processing unit and a lithographic system, and a device manufacturing method. More particularly, the present invention relates to an exposure apparatus used in a lithographic process when producing a semiconductor element, a liquid crystal display, a plasma display, a thin film magnetic head, an image pick-up device (CCD), a microdevice such as a micromachine, and furthermore, a photomask (reticle) and the like, a substrate processing unit which is in-line connected to the exposure apparatus, and a lithographic system which arrangement includes the exposure apparatus and the substrate processing unit, and a device manufacturing method employing the exposure apparatus and the lithographic system.
2. Description of the Related Art
In the lithographic process to produce a microdevice such as a semiconductor element and the like referred to above, various exposure apparatus were used in general. In recent years, the exposure apparatus that transfers a pattern formed on a mask or a reticle (hereinafter generally referred to as a xe2x80x9creticlexe2x80x9d) onto a substrate such as a wafer or a glass plate (hereinafter generally referred to as a xe2x80x9cwaferxe2x80x9d) coated with a photoresist (photosensitive agent) via a projection optical system is mainly used. Of the exposure apparatus, the reduction projection exposure apparatus (the so-called stepper) based on the step-and-repeat method was the mainstream. However, the usage of the scanning type exposure apparatus (the so-called scanning stepper) based on the step-and-scan method, which performs exposure by synchronously scanning the reticle and the wafer in respect to the projection optical system, has lately increased.
The lithographic process includes a resist coating process to coat the resist onto the surface of the wafer and a development process to develop the wafer after completing the reticle pattern transfer, performed before and after the exposure process that uses the exposure apparatus. And in the resist coating process and the development process, a coating/development unit called a coater developer (hereinafter abbreviated as xe2x80x9cC/Dxe2x80x9d) is used. This coater developer has the function of both a resist coating unit (a coater) such as a spin coater which, for example, spins the wafer at a high speed and utilizes the rotation of the wafer to evenly coat drops of resist dripped onto the surface of the wafer, or a scan coater which relatively moves the nozzle and the wafer, and a development unit (a developer).
In the lithographic process, a system arrangement, which is widely called as an in-line connection, is frequently employed. With the in-line connection, the C/D is arranged, for example, on the left, right, or the front (or the back) of the exposure apparatus and is connected directly or via a connecting portion to the exposure apparatus, and the body subject to processing (wafer subject to processing) is carried automatically in between the C/D and the exposure apparatus. The purpose for employing this system arrangement is to avoid complication when delivering the processing lot (the wafer lot subject to processing) to each of the resist coating process, the exposure process, and the development process, and to also improve the throughput while maintaining the chemical properties in the chemically amplified resist, which is a type of resist with high sensitivity frequently used nowadays.
In the lithographic system employing such an in-line connection between the exposure apparatus and the C/D, in most cases, a delivery portion is arranged in between the exposure apparatus and the C/D to perform delivery of the wafer between these units. In addition, the C/D has a carriage system within the unit that circulates the wafer subject to processing under a fixed process between the coating portion where the coating process is performed and the development portion where the development process is performed. The exposure apparatus also has a carriage system within the unit, and circulates the wafer subject to processing between the wafer stage where the exposure is performed and the delivery portion.
Moreover, with the lithographic process described above, in many cases, a cooling portion and a bake portion are arranged when necessary. Furthermore, a buffer portion to temporarily house the wafer subject to processing is also arranged when necessary.
In the lithographic system employing the in-line connection of the exposure apparatus and the C/D, when delivery of the wafer is performed at the delivery portion, the exposure apparatus and the C/D communicate with each other so that the delivery of the wafer is performed without fail. Therefore, the exposure apparatus and the C/D respectively have a control portion that performs communication and carriage control.
In the conventional lithographic system, however, the exposure apparatus and the C/D communicated on issues related to the delivery of the wafer at the delivery portion such as the delivery request, the possibility/forbiddance of delivery, and the completion of delivery and the like only real time, step by step.
This caused circumstances such as the exposure apparatus not being able to receive the wafer, when the C/D circulates the wafer under the fixed procedure so as to perform optimal carriage within the unit and tries to deliver the wafer that has not yet been exposed during the carriage to the exposure apparatus through the delivery portion. Or, the C/D could not receive the wafer that has completed exposure at the exposure apparatus side through the delivery portion, because the wafer had not yet arrived at the delivery portion. This situation led to a longer waiting time, and in some cases, the delivery ended in failure since no wafers were ready for delivery due to the difference in timing of the circulation carriage within the respective units, and the wafer carriage was suspended until the next circulation timing.
Whereas, with the exposure apparatus, the operation is efficient when the wafer is processed continuously on the wafer stage. Therefore, in order to avoid the situation where there are no wafers to process on the wafer stage as much as possible, the loading of the wafer onto the wafer stage and the unloading of the wafer from the wafer stage need to be performed alternately or simultaneously. With the wafers that have been exposed, the wafers need to be unloaded without the time spent on each wafer differing and sent to the next process of bake/development performed by the C/D as quickly as possible, since the chemical change of the wafer is continuous.
Considering such circumstances, the exposure apparatus side performs wafer carriage in the order of loading the wafer into the apparatus and then unloading the wafer outside the apparatus. There were times, however, when the exposure apparatus tried to receive the wafer that has not yet been exposed from the delivery portion but could not since the C/D side had not yet delivered the wafer, or, when the exposure apparatus tried to deliver the wafer that has completed exposure to the C/D through the delivery portion but could not since the C/D side was not in a state to receive the wafer. In these cases, the exposure apparatus waits for a certain period and monitors the situation to see if the wafer that has not yet gone through the exposure process is delivered. And if the wafer is not delivered and exposure process is completed at that stage, the exposure apparatus suspends the wafer loading, and switches the circulation operation to the unloading operation of the wafer that has completed the exposure process. Therefore, the situation occurred at times where the delivery ended in failure or where the exposure apparatus had to wait for delivery at the delivery portion.
The description above describes the case when the carriage system of the exposure apparatus performs the loading and unloading of the wafer alternately, however, even if the carriage system performs the loading simultaneously, the restrictions at the delivery portion inevitably cause the exposure apparatus to wait for the delivery of the wafer.
That is, the C/D unit and the exposure apparatus were capable of respectively completing their predetermined procedures and operating in optimal on their own. However, when the C/D unit and the exposure apparatus were linked to each other with the delivery portion as the center, the circulation operation of the wafer carriage on the C/D side did not correspond with the circulation operation of the wafer carriage on the exposure apparatus side. This situation often caused a waste of time in waiting for the wafer and also caused the delivery to end in failure, which led to a decrease in throughput.
Nevertheless, the decrease in throughput due to the waiting time and the failure in delivery was not a serious problem, since conventionally, the size of the wafer used was mainly 8 inches (approximately 200 mm) and under in diameter and the wafer control was performed per lot.
The wafer, however, is becoming larger in size with higher integration of the semiconductor element, and in future, it is said that the wafer having the diameter of 12 inches (approximately 300 mm) will become mainstream and the wafer control per wafer will become mandatory. With the practice performing such wafer control, it is certain that the decrease in throughput due to the waiting time and the failure in delivery referred to above will be a more serious problem, compared with the conventional practice.
The present invention has been made in consideration of the circumstances described above, and has as its first object to provide an exposure apparatus that is in-line connected with a substrate processing unit and is capable of improving the throughput in a series of substrate processing.
It is the second object of the present invention to provide a substrate processing unit that is in-line connected with an exposure apparatus and is capable of improving the throughput in a series of substrate processing.
And, it is the third object of the present invention to provide a lithographic system and a device manufacturing method that can improve the productivity of a device by improving the throughput in a series of substrate processing.
According to the first aspect of this invention, there is provided an exposure apparatus which is in-line connected with a substrate processing unit, the exposure apparatus comprising: a substrate carriage system which carries a substrate and delivers a substrate between the substrate processing unit via a delivery portion; and a control unit which structures a control system to control the substrate carriage system, the control unit performing at least one of transmitting and receiving specific information between the substrate processing unit in advance to decide an operation that contributes to improvement in processing capacity related to substrate carriage.
In this description, the term xe2x80x9cinformationxe2x80x9d is used in a broad sense, and includes the concept of signals other than data or a group of data.
According to the exposure apparatus, the control unit at least transmits or receives in advance specific information between the substrate processing unit, to decide its operation that contributes to improvement in processing capacity related to substrate carriage. For example, in the case the control unit transmits the specific information to the substrate processing unit in advance, it can make the substrate processing unit decide its operation that contributes to improvement in processing capacity related to substrate carriage before the operation actually begins. On the other hand, when the control unit receives the specific information from the substrate processing unit in advance, it can decide its operation that contributes to improvement in processing capacity related to substrate carriage before the operation actually begins.
Accordingly, in either case, the processing capacity in the series of substrate processing performed by the substrate processing unit and the exposure apparatus, in other words, the throughput can be improved. Especially, when the control unit receives the specific information from the substrate processing unit in advance, as well as transmits the specific information to the substrate processing unit in advance, it can decide its own operation that contributes to improvement in processing capacity related to substrate carriage before the operation actually begins, in addition to making the substrate processing unit decide its operation that contributes to improvement in processing capacity related to substrate carriage before the operation actually begins. Therefore, it becomes possible to improve the throughput in the series of substrate processing performed by the substrate processing unit and the exposure apparatus to the utmost.
In this case, the control unit can transmit information to the substrate processing unit so that the substrate processing unit can decide its following operation that contributes to improvement in processing capacity related to substrate carriage, the information transmitted prior to starting the following operation as the specific information. In such a case, the control unit transmits information to make the substrate processing unit decide its following operation that contributes to improvement in processing capacity related to substrate carriage to the in-line connected substrate processing unit, prior to the start of the following operation. So, when the substrate processing unit receives the information, it can decide to perform the specific operation that contributes to improvement in processing capacity related to substrate carriage as its following operation beforehand, that is, decide to perform the specific operation before actually starting the specific operation. Accordingly, it becomes possible to improve the throughput in the series of substrate processing performed by the substrate processing unit and the exposure apparatus.
In this case, the information can include one of a predicted time and an expected time until the substrate carriage system is capable of receiving a substrate. In such a case, since the substrate processing unit side can acknowledge the timing when the substrate carriage system of the exposure apparatus side can receive the substrate, it can decide its next operation related to substrate carriage so that the substrate can be delivered with the least time wasted. For example, when the time until the substrate carriage system of the exposure apparatus side can receive the substrate is short, such as one or two seconds, then, the substrate processing system can wait to deliver the substrate, whereas, if the waiting time is long, then it can suspend delivering the substrate and just receive the substrate from the delivery portion. Then, the loss of time can be reduced.
Or, the information can include information so as to make the substrate processing unit side withhold carriage of a substrate to the delivery portion. In such a case, for example, the control unit sends information to the substrate processing unit such as to wait for a predetermined seconds to carry the substrate to the delivery portion until the substrate can be received. In this case, also, the substrate processing unit can decide its operation related to efficient carriage of the substrate so as to reduce the loss of time as much as possible, depending on the waiting time.
Or, the information can include one of a predicted time and an expected time until the substrate carriage system is capable of sending out a substrate. In such a case, for example, if the substrate that has been exposed is to be delivered from the exposure apparatus side within a few seconds, the substrate processing unit which receives the information can wait for a few seconds upon receiving the substrate. Thus, the delivery does not have to end in failure, and can be efficiently performed.
Or, the information can include information so as to make the substrate processing unit side withhold operations to receive a substrate at the delivery portion. In such a case, for example, the control unit sends information to the substrate processing unit such as to wait for a predetermined seconds so that the substrate can be delivered. In this case, as well, the substrate processing unit can decide its operation related to efficient carriage of the substrate so as to reduce the loss of time as much as possible, depending on the waiting time.
With the exposure apparatus according to the present invention, in the case the control unit transmits information to the substrate processing unit so that the substrate processing unit can decide its following operation that contributes to improvement in processing capacity related to substrate carriage, prior to starting the following operation as the specific information, the control unit can further receive information related to substrate carriage from the substrate processing unit as the specific information, and based on the information, can determine in advance its following operation that contributes to improvement in processing capacity related to substrate carriage. In such a case, the control unit receives information related to substrate carriage from the substrate processing unit, and based on the information, decides in advance its following operation that contributes to improvement in processing capacity related to wafer carriage. Therefore, in addition to the efficiency related to the substrate carriage on the substrate processing unit side, the efficiency related to the substrate carriage on the exposure unit side is also improved. Accordingly, it becomes possible to further improve the throughput in the series of substrate processing performed by the substrate processing unit and the exposure apparatus.
With the exposure apparatus according to the present invention, the control unit can receive information related to substrate carriage from the substrate processing unit as the specific information, and based on the information, can determine in advance its following operation that contributes to improvement in processing capacity related to substrate carriage. In such a case, the control unit receives information related to substrate carriage from the substrate processing unit, and based on the information, determines in advance its following operation that contributes to improvement in processing capacity related to substrate carriage. Therefore, the processing capacity in the series of substrate processing operation performed by the substrate processing unit and the exposure apparatus, that is, the throughput, can be improved.
In this case, the information can include one of a predicted time and an expected time until the substrate processing unit side is capable of sending out a substrate. In such a case, the control unit can acknowledge the timing when the substrate processing unit side can deliver the substrate; therefore, it can decide its next operation related to substrate carriage so that the substrate can be received with the least time wasted. For example, when the time until the substrate processing unit side can deliver the substrate is short, such as one or two seconds, then, the control unit can wait to receive the substrate, whereas, if the waiting time is long, then it can suspend receiving the substrate and just deliver the substrate. Then, the loss of time can be reduced. That is, fruitless operation such as waiting for a certain period of time to receive the substrate can be avoided.
Or, the information can include information so as to make the substrate carriage system withhold operations to receive a substrate at the delivery portion. In such a case, for example, the substrate processing unit sends information to the control unit such as to wait for a predetermined seconds until the substrate can be delivered. In this case, as well, the control unit can decide its operation related to the most efficient carriage of the substrate possible, according to the waiting time.
Or, the information can include one of a predicted time and an expected time until the substrate processing unit side is capable of receiving a substrate. In such a case, for example, if the substrate that has been exposed can be received by the substrate processing unit side within a few seconds, the control unit, which receives the information, can wait for a few seconds to deliver the substrate. And if a long wait is required until the substrate can be received, then it becomes possible to perform other operations first, such as receiving operations, and then deliver the substrate to the substrate processing unit. Thus, the delivery does not have to end in failure, and the efficiency is improved.
Or, the information can include information so as to make the substrate carriage system withhold operations to send out a substrate to the delivery portion. In such a case, for example, the substrate processing unit sends information to the control unit such as to wait for a predetermined seconds until the substrate can be received. In this case, as well, the control unit can decide its operation related to the most efficient carriage of the substrate possible, in accordance with the waiting time.
According to the second aspect of this invention, there is provided a substrate processing unit which is in-line connected with an exposure apparatus, the substrate processing unit comprising: a substrate carriage system which carries a substrate and delivers a substrate between the exposure apparatus unit via a delivery portion; and a control unit which structures a control system to control the substrate carriage system, the control unit performing at least one of transmitting and receiving specific information between the exposure apparatus in advance to decide an operation that contributes to improvement in processing capacity related to substrate carriage.
With the substrate processing unit, the control unit at least transmits or receives in advance specific information between the exposure apparatus, to decide its operation that contributes to improvement in processing capacity related to substrate carriage. For example, in the case the control unit transmits the specific information to the exposure apparatus in advance, it can make the exposure apparatus decide its operation that contributes to improvement in processing capacity related to substrate carriage before the operation actually begins. On the other hand, when the control unit receives the specific information from the exposure apparatus in advance, it can decide its operation that contributes to improvement in processing capacity related to substrate carriage before the operation actually begins.
Accordingly, in either case, the processing capacity in the series of substrate processing performed by the substrate processing unit and the exposure apparatus, in other words, the throughput can be improved. Especially, when the control unit receives the specific information from the exposure apparatus in advance, as well as transmits the specific information to the exposure apparatus in advance, it can decide its own operation that contributes to improvement in processing capacity related to substrate carriage before the operation actually begins, in addition to making the exposure apparatus decide its operation that contributes to improvement in processing capacity related to substrate carriage before the operation actually begins. Therefore, it becomes possible to improve the throughput in the series of substrate processing performed by the substrate processing unit and the exposure apparatus to the utmost.
In this case, the control unit can transmit information to the exposure apparatus so that the exposure apparatus can decide its following operation that contributes to improvement in processing capacity related to substrate carriage, the information transmitted prior to starting the following operation as the specific information. In such a case, the control unit transmits information to make the exposure apparatus decide its following operation that contributes to improvement in processing capacity related to substrate carriage to the in-line connected exposure apparatus, prior to the start of the following operation. So, when the exposure apparatus receives the information, it can decide to perform the specific operation that contributes to improvement in processing capacity related to substrate carriage as its following operation beforehand, that is, decide to perform the specific operation before actually starting the specific operation. Accordingly, it becomes possible to improve the processing capacity in the series of substrate processing performed by the exposure apparatus and the substrate processing unit, that is, to improve the throughput.
In this case, the information may include one of a predicted time and an expected time until the substrate carriage system is capable of receiving a substrate, or the information may include information so as to make the exposure apparatus side withhold carriage of a substrate to the delivery portion, or the information may include one of a predicted time and an expected time until the substrate carriage system is capable of sending out a substrate, or the information may include information so as to make the exposure apparatus side withhold operations to receive a substrate at the delivery portion.
With the substrate processing unit according to the present invention, when the control unit transmits information to the exposure apparatus so that the exposure apparatus can decide its following operation that contributes to improvement in processing capacity related to substrate carriage, and the information is transmitted prior to starting the following operation as the specific information, the control unit can further receive information related to substrate carriage from the exposure apparatus as the specific information, and based on the information, can determine in advance its following operation that contributes to improvement in processing capacity related to substrate carriage. In such a case, the control unit receives information related to substrate carriage from the exposure apparatus, and based on the information, decides in advance its following operation that contributes to improvement in processing capacity related to wafer carriage. Therefore, in addition to the efficiency related to the substrate carriage on the exposure apparatus side, the efficiency related to the substrate carriage on the substrate processing unit side is also improved. Accordingly, it becomes possible to further improve the throughput in the series of substrate processing performed by the substrate processing unit and the exposure apparatus.
With the substrate processing unit according to the present invention, the control unit can receive information related to substrate carriage from the exposure apparatus as the specific information, and based on the information, can determine in advance its following operation that contributes to improvement in processing capacity related to substrate carriage. In such a case, the control unit receives information related to substrate carriage from the exposure apparatus, and based on the information, determines in advance its following operation that contributes to improvement in processing capacity related to substrate carriage. Therefore, the processing capacity in the series of substrate processing operation performed by the substrate processing unit and the exposure apparatus, that is, the throughput, can be improved.
In this case, the information may include one of a predicted time and an expected time until the exposure apparatus side is capable of sending out a substrate, or the information may include information so as to make the substrate carriage system withhold operations to receive a substrate at the delivery portion, or the information may include one of a predicted time and an expected time until the exposure apparatus side is capable of receiving a substrate, or the information may include information so as to make the substrate carriage system withhold operations to send out a substrate to the delivery portion.
According to the third aspect of this invention, there is provided a lithographic system, the system comprising: an exposure apparatus; and a substrate processing unit which is in-line connected to the exposure apparatus, the processing unit transmitting and receiving information related to carriage of a substrate between the exposure apparatus, wherein at least one of the exposure apparatus and the substrate processing unit decides its following operation that contributes to improvement in processing capacity related to substrate carriage based on the information, prior to starting the following operation.
With the lithographic system, information related to substrate carriage is transmitted and received between the exposure apparatus and the substrate processing unit, and by at least either of the unit, its following operation that contributes to improvement in processing capacity related to substrate carriage is decided prior to starting the operation based on the information. This allows the processing capacity in the series of substrate processing performed by the substrate processing unit and the exposure apparatus, in other words, the throughput to be improved, and as a consequence, becomes possible to improve the productivity of the device. Especially in the case when both units decide their following operation that contributes to improvement in processing capacity related to substrate carriage prior to starting the operation based on the information, the throughput can be improved to the utmost.
In this case, for example, information on the predicted time or the expected time until the substrate can be received or sent out can be reciprocally notified between both units.
With the lithographic system in the present invention, in the case the information transmitted and received between the exposure apparatus and the substrate processing unit includes withholding information to make a unit other than itself withhold carriage operations of a substrate, and the withholding information is concurrently sent by both the exposure apparatus and the substrate processing unit, a unit to which preference is given in advance can send information to the unit other than itself to dismiss its withholding request, and the unit other than itself can withdraw the withholding request in accordance with the dismissal request information. In such a case, likewise as above, the processing capacity in the series of substrate processing performed by the substrate processing unit and the exposure apparatus, in other words, the throughput can be improved.
With the lithographic system according to the present invention, the information may be communicated directly between the exposure apparatus and the substrate processing unit, or the lithographic system may further comprise a separate unit which acts as an intermediary when the information is transmitted and received between the exposure apparatus and the substrate processing unit.
With the lithographic system according to the present invention, in the case the lithographic system further comprises: a superior unit which has total control over the exposure apparatus and the substrate processing unit, the information transmitted and received between the exposure apparatus and the substrate processing unit can include withholding information to make a unit other than itself withhold carriage operations of a substrate, and when the withholding information is concurrently sent by both the exposure apparatus and the substrate processing unit, the superior unit may totally judge from the viewpoint of improving the processing capacity to send information to one of a predetermined unit to dismiss its withholding request to make the predetermined unit withdraw the withholding request.
According to the fourth aspect of this invention, there is provided a first device manufacturing method to manufacture a device using a lithographic system which comprises an exposure apparatus and a substrate processing unit in-line connected to the exposure apparatus, the device manufacturing method comprising: transmitting and receiving information related to carriage of a substrate between the exposure apparatus and the substrate processing unit; and at least one of the exposure apparatus and the substrate processing unit decides its following operation that contributes to improvement in processing capacity related to substrate carriage based on the information, prior to starting the following operation.
With this method, the processing capacity in the series of substrate processing performed by the substrate processing unit and the exposure apparatus, in other words, the throughput, can be improved, and as a consequence, it becomes possible to improve the productivity of the device. Especially, in the case when both units decide their following operation that contributes to improvement in processing capacity related to substrate carriage prior to starting the operation based on the information, the throughput can be improved to the utmost.
In addition, in the case the exposure apparatus according to the present invention is used in the lithographic process, since the exposure apparatus is used having in-line connection with the substrate processing unit, the throughput in the series of substrate processing performed by these units can be improved, and this consequently allows the productivity of the device manufactured to be improved. Accordingly, from another aspect of the present invention, there is provided a second device manufacturing method that uses the exposure apparatus of the present invention.